The harmonic curves of all Woldsong harps are designed so that the placement of the bridge pins follow a true "harmonic curve", actually a mathematical term indicating a parabola.
Foreshortening is, basically, the process of increasing string MASS rather that string LENGTH to produce lower tones. Following the theoretically correct curve makes the "foreshortening" of the strings very regular from string to string. The only places where this varies slightly is at the half steps. I am not aware of any other harp that adheres to this detail. (If you're really interested, there's a more thorough explanation in the FAQ area via the Woldsong Home Page).
The important thing is that I try to whatever degree possible to maintain the consistant overtone structure and thus through greater sympathetic vibrations in the overtones give the harp greater presence through its entire range.
On most harps, the foreshortening is random and haphazard. Following the theoretically correct layout makes the overtone structure of the sounds from each string more consistant and sympathetic vibrations of the strings is greater. This gives the harp a greater sound presence and more voice.